Photocomposing machines



Sept. 16, 1969 HOFFMANN ET AL 3,466,991

PHOTOCOMPOSING MACHINES Filed 001:. 28, 1966 2 Sheets-Sheet 1 INVENTORS MEINHARD HOFFMAN ERICH ADLER KARL-JURGEN DEBUS United States Patent 3,466,991 PHOTOCOMPOSING MACHINES Meinhard Hotfmann, Dornigheim, Erich Adler, Russelsheim, and Karl-.liirgen Debus, Bad Homhnrg, Germany, assignors to Linotype G.m.b.H., Frankfurt am Main, Germany, a limited liability corporation of Germany Filed Oct. 28, 1966, Ser. No. 590,384 Int. Cl. B41b 13/18 U.S. Cl. 954.5 4 Claims ABSTRACT OF THE DISCLOSURE In a phototypograph in which selected character images are distributed to form a line of text along a section of film held in a fixed position, by a reflector rotated continuously during line composition, there is provided means for measuring the extent of rotation of the reflector, and means for intermittently flashing the light source to project a selected character when the reflector is moved a distance corresponding to the set width of the character previously printed.

This invention relates to photocomposing machines and more particularly to a means for projecting images of selected characters from a stationary font plate to a sensitized sheet that is held in fixed position during line composition.

The prior art discloses many mechanisms for selecting and reproducing phototypographical characters including letters and symbols on a sensitized sheet. Thus it is known to arrange the letters and symbols on a square carrier or font plate at right angles above and besides each other, and to select a certain letter or symbol with the help of a shutter consisting of several apertures, moveable against each other. In another mechanism a lens is moved along a letter or symbol magazine and selects, according to its position, a letter or symbol. Both mechanisms are expensive to manufacture and require a very exact mechanical construction. Another known photocomposing mechanism employs a mirror carriage running on a straight line, and shiftable lenses. This also requires very exact and consequently expensive mechanical guides. In brief, all known commercial photocomposing machines employ, in one form or another, straight line movements which are difficult and expensive to manufacture.

It has been found that the defects and disadvantages of the known devices for the selection and reproduction of letters and symbols can be avoided in a very simple way, if from a carrier of letters and symbols, equipped with a light source, a light beam is directed towards a deflecting means which is rotated to deflect the light beam to a fixed image plane curved concentrically to the turning axis of the deflecting means. A continuously rotating element, which is graduated in units of a typographical width, pivots the deflecting means from a start of line position to an end of line position. When the deflecting means reaches the end of line position a clutch disengages it from the rotating element, which continues its rotation, thereby permitting the deflection means to be restored to its start of line position. During the traverse of the deflecting means from its start of line position, the light source that illuminates the font of characters is flashed when the deflecting means is advanced a distance corresponding to the width of the character selected for exposure thus projecting the character image to a photosensitized sheet located in the image plane.

Preferably the mechanism provided in accordance with ice the invention is further advantageously designed by using as a rotating body a disc the periphery of which contains radial slits, the spacing of which is defined by typographic measuring units of fractions of the same; by converting the dimension of the angular distance covered by the disc, via the connected deflecting means as the length of path of the optical axis on the carrier of the photosensitive material, with the help of scanning means assigned to the slots into digital values; by continuously comparing the counted values with the values predestined (stored) that correspond to the width of the character to be recorded; and by actuating, when reaching coincidence, the light source for the letter or symbol to be reproduced.

In accordance with the invention prisms are preferably used as deflecting means. The simplicity of the other components permit the use of standard, readily available parts to a large extent, and thus achieve a comparatively very high accuracy of reproduction at comparatively little cost. The light paths are short and, therefore, need little space resulting in a small, compact photocomposing machine.

In carrying out the invention, a prism is preferably mounted on a rotatable arm for pivoting movement. The arm is provided with a gear segment which engages a gear Wheel which in turn is connectable to a driving motor by means of a clutch. The clutch is preferably a solenoid type. The prism, via a further arm, is connected to a permanently effective tension spring which returns the prism to a start of line position when the clutch is deenergized. The motor also drives a disc the periphery of which is slotted to provide an indication of the degree of rotation of the motor, and hence, of the prism. A light source and a photocell or similar means are positioned with respect to the disc so that the passage of the disc slots are converted into pulses that can be compared to character width information otherwise provided in the apparatus.

It was further found that the carrier of the photosensitive material is preferably a spoolable film strip; and that two spools, a feed and a take-up spool, are used which cover between themselves the reproduction area of the film strip. Further means are provided which give to the film strip within the reproduction area a curvature, concentric to the axis of the swinging prism.

Further characteristics, advantages, and applications of the new invention can be taken from the accompanying drawings as well as from the following description.

In the drawings:

FIGURE 1 is a schematic view of the present invention;

FIGURE 2 is a schematic elevational view partly in section showing the swinging prism mechanism;

FIGURE 3 is a schematic plan view of the mechanism shown in FIGURE 2; and

FIGURE 4 is a block diagram showing the functional control of the mechanism.

That part of the device which serves for the selectlon of letters or symbols is, in case of the invention, a preferred design which is principally characterized by one or several rows of characters, i.e., letters or symbols, being placed. on a carrier and by a light source being mounted behind these characters to project light through the character negatives. Moreover, the character negatives are provided with individual associated deflecting means which are selectively actuated into the path of the light projected through a character negative so as to transmit only that light from a selected character to the sensltlzed sheet fixedly held in the reproduction plane. The font plate and the remaining components of the system are arranged such that the distances from the optical centers of each character to its assocated deflecting means, to the common prism, and to the sensitized sheet are equal.

Reference is now made to the drawings wherein a barshaped carrier 1 is shown with character negatives 2 and 3, which may be letters, numerals, or other symbols, placed in separate mountings and arranged in two horizontal rows. These mountings, e.g., cylindrical inserts, are mounted in such a way that they can be moved in their longitudinal axis and are, thus, adjustable. Preferably, the inserts should be exchangeable. The letters or symbols are set in a negative position, e.g., on photographic film, and fixed in the inserts. The letters are suitably divided into upper case and lower case and placed in separate rows, one above the other. Behind the carrier 1 a light source is placed which, in the illustrated example, is a rod-shapedflash lamp 4 common for each row of characters. To each letter of symbol is assigned its own deflecting prism. All prism are mounted on a carrier 5 for movement one at a time vertically to the plane of reproduction. This carrier is arranged in the illustrated example at an angle of 45 in relation to the carrier 1 of letters and symbols, and in this way the light paths from all character negatives are of equal distance to the film holder. The prisms, i.e., 6, 7, are moved individually and selectively into operative position with the help of solenoids, e.g., 10, 11, and levers 12 or 13. The energization of a solenoid is controlled by means not illustrated but which may be from perforated paper control tape of the photo composition machine, or directly from a keyboard.

All deflecting prisms belonging to one row of letters or symbols, be it upper or lower case, are placed in one row, behind each other. Each light beam coming from any moved prism in each row is directed into the optical axis common to all light beams from that row. Therefore, in the embodiment illustrated, there are two such axes since the character negatives are arranged in two rows. One of these axes may directly coincide with the optical axis 15 of the purely schematically illustrated reproduction system 16 which may, for instance, contain optical lenses. Consequently, the other axes must be brought into coincidence with axis 15, and this is accomplished by the switchable deflecting device 14 which might be termed an upper-lower case switch. The operating mechanism for this device 14 is not shown, but its function and movement is well understood by those skilled in the art.

The system 16 is fixedly mounted in the photocomposing machine. The aforementioned angle of 45 between the carrier 1 and the prism carrier 5 has the special advantage that, with a fixed assembly of the system 16, the optical distances between each letter or symbol via its attached prism to the reproduction system 16 and further to the reproduction plane are always equal. In this way the definition of each letter or symbol is always microscopically sharp. Preferably, the planes of the letters and symbols should be vertical in relation to their light beam, and the prisms should be equal sided, right angle prisms (90 prisms) onto which the arriving light beam is directed vertically and from which, after a deflection of 90, it also emerges vertically.

The light ray or light beam emerging from the optical system 16 enters a pivoting prism 17, which is also 90 prism (see FIGURES 2 and 3), and which deflects the light ray or light beam to the place of reproduction which, in the illustrated example, is a film strip 18. This strip is curved in the area where it is to receive the character images. The radius of curvature is defined as R, and the axis of curvature 19 is identical to the turning axis of the prism 17 (FIGURE 1). The film strip 18 is taken off a lower supply spool and taken up on the upper spool 21. The film driving mechanism, which can be of standard design, is not illustrated. The means to achieve film curvature in the image area can be of standard design. In the illustrated example a rubber-covered spiral spring 22, the longitudinal axis of which is curved to correspond with the radius given, is used. The spiral spring rotates around its axis and is mounted in ball bearings 23. In front of the strip 18 an aperture mark 24 is located, mainly to exclude stray light.

The prism 17 is mounted on a shaft 25 which is moveably located in a bearing 26 and onto which two arms 27 and 28, forming a wide angle, are fixed. The other side of the lever 28 is connected to a tensioning spring 29, the opposite end of which is connected to a fixed point. The other end of the lever 28 carries a toothed segment 31 into which engages the toothed rim of a spur gear 32, which is mounted on a pivot 34, turnably located in a bearing 35. The toothed rim of gear 32 may also be interrupted peripherally. To the opposite end of the pivot 34 is mounted a clutch disc 36, a short distance from which its counterpart 37 is located and on the axis of which a clutch gear wheel 38 is fixed. The spindle 39 of this gear wheel is axially moveable by means of a solenoid device 40. The control of the solenoid, not illustrated, may also be effected by perforated paper tape controlling the photo composition machine.

The gear wheel 38 engages an intermediate gear wheel 41 the spindle 42 of which rotates in a bearing 43. The other end of the spindle 42 is firmly connected to a spur gear 44 which engages a bevel gear 45. The bevel gear is firmly mounted on a spindle 46 as is a worm gear 47. Gear 47 engages the worm 48 which is driven by its own electric motor 65. The motor runs continuously in one direction during operation of the apparatus. The turnable spindle 46, also described as intermediate drive spindle, is located in bearings 49 and 50. Opposite the bevel gear 45 the spindle 46 carries a disc 51, the periphery of which has slots, i.e., 52, 53, 54, which are uniformly spaced apart at distances that are identical to the smallest counting unit of the set width values of letters and symbols of any font. It is very advantageous to use the part of a Cicero (typographical measuring unit in the Didot system) or of a pica (typographical unit in the English system). In place of a sloted disc, a transparent disc having alternating opaque and transparent areas, may be used.

In the area of the slots 52, 53, 54, a light barrier is placed consisting principally of a light source 55 and a photo cell 56. When operating the machine, the prism 17 and the slotted disc 51 are put into motion first. With the help of a light barrier 64, or a similar device, actuated by the lever arm 27, the reader 58 is put into operation when the optical axis projected by prism 17 intersects the start of line position on film 18.

When reading a letter or symbol information, the reader 58 passes impulses corresponding to the letter width to the counting value encoder 61 via the decoder 59 and a counting magazine 60. Also, an impulse from the decoder 59 is passed to a solenoid 10 so that the light from the selected character will be projected to the film 8, the light from the other characters passing over their associated prisms away from the film. However, if the reader 58 reads an instruction information, impulses are only passed to an instruction address 62 which, in turn, actuates, for example, the upper-lower case switching device 14.

Suppose the reader 58 reads a letter or symbol combination, the impulse is passed, as aforesaid, to the counting value encoder 61. The value converted by the counting value encoder 61, now a binary value, is passed into a counter 63. The impulse also is transmitted to the solenoid 10 which is assigned to the prism 6 which is associated with the letter or symbol 2 to be selected. The impulse causes the prism 6 to be brought into the light beam 8 of the selected letter or symbol 2.

By means of the impulses coming from the light barrier 55, 56, located at the already rotating slotted disc, the counter 63 is emptied. At the moment when the counter is completely empty, the light source (flash lamp) 4 is made operative. The selected letter or symbol 2 is reproduced on the film strip 18 bearing the photosensitive material, via its deflecting prism 6, the upper-lower case switching device 14, the optical system 16, and the swinging prism 17. In the same manner, the following letters and symbols are being reproduced.

When a word is completed a distance, representing an interword space, is passed by the prism between the last letter of the completed and the first letter of the following word, this inter-word space is controlled by a spaceband signal. In this case, the light source 4 remains inoperative and no solenoid for the movement of a deflecting prism is actuated. When the prism has passed the interword space, the reproduction of the next word begins.

At the end of a line of composition the solenoid clutch 40 is made ineffective by means of a switch, the reader 58 is stopped and, at the same time, the swinging prism 17 returns to its starting position with the help of the return spring 29. In the same way the next line is set.

It is to be understood that many changes and variations can be made to the disclosed embodiment without departing from the spirit or scope of the invention and, there fore, the description and the drawings are to be interpreted in an illustrative rather than a limiting sense.

What is claimed is:

1. A photocomposing apparatus comprising a character font assembly, a sensitized sheet holder, a light source for projecting light through the characters for-med on said font assembly, a plurality of light deflecting means, one for each character provided on said font assembly, said light deflecting means and said character font assembly being arranged such that the light paths from each of the characters on said font assembly to its associated light deflecting means to the sensitized sheet holder are all equal in distance, means for selectively actuating said light deflecting means so that the light projected through a single character is deflected towards said sensitized sheet holder, a rotatably mounted prism for intercepting the light projected from a selected character, means for rotating said prism continuously during line composition, means for measuring the extent of prism rotation, and means for intermittently flashing said light source to image a selected character when the prism is moved a distance corresponding to the set width of a previously imaged character whereby images of successively selected characters are photographed in side by side relationship .on a sensitized sheet held in said sheet holder.

2. A photocomposing apparatus according to claim 1 wherein the prism rotating means includes a one directional continuously running motor, and including a clutch means for disengaging the prism from said motor drive at the completion of a line of composition, and spring means for restoring the prism to its start of line position.

3. A photocomposing apparatus according to claim 1 wherein the image receiving area of the sheet holder is formed in an arc concentric with the axis of rotation of the prism.

4. A photocomposing apparatus according to claim 1 wherein the character font assembly comprises a plurality of individual character inserts, each removably mounted in a font holder.

References Cited UNITED STATES PATENTS JOHN H. HORAN, Primary Examiner 

